Was getting ready to clean up the boat and get it ready for my next road trip and went to turn on some tunes while I worked. Nothing.. Syn6 and Syn4 fire up fine, no error codes. 420 comes up, lights up, but no output--no towers, sub or inboats. Bypassed the inboats output and connected my ipod directly and the speakers work. What else could I test? If it was a fuse, it wouldn't power up at all would it? Scrambling because I leave on Wednesday for a 5 day houseboat trip and really don't want to go without tunes. Any advice is appreciated. Oh, and out of warranty unfortunately.